1. Field of the Invention
This application claims the priority of Korean Patent Application No. 2002-54940, filed Sep. 11, 2002 in the Korean Intellectual Property Office, which is incorporated herein in its entirety by reference.
The present invention relates to a speech recognition apparatus, and more particularly, to a device for performing a dynamic time warping method for speech recognition and a speech recognition apparatus using the device.
2. Description of the Related Art
According to a general speech recognition method, a test pattern, which is obtained by patterning a speech signal to be suitably recognized for matching, is matched with a plurality of reference patterns that are in advance stored corresponding to words to be recognized. Next, a reference pattern, which is selected to most suitably match the test pattern, is recognized as the word of an input speech signal.
To classify the best matching reference pattern, various pattern classification methods are used. Among these there are a hidden markov model (HMM) method that statistically models a test pattern and classifies reference patterns, a time delay neural network (TDNN) method, and a dynamic time warping (DTW) method that enables effective classification of the optimum reference pattern even if there is a difference between the length of times of a test pattern and a reference pattern.
Conventionally, for classification of the optimum reference pattern, speech recognition software must be stored in a general computer and then operated by the computer. This triggers a need to develop a hardware that is small sized and operates at a high speed and with a high speech recognition ratio, using a speech recognition system based on a speech recognition software for dynamically time warping of a test pattern and a reference pattern.